Fighting Disease - Vaccination

Question 1

When you are infected with a new pathogen, why can you still be ill when you have white blood cells for defence?

Answer 1

It takes your white blood cells a few days to learn how to deal with it. By that time you can be ill.

Question 2

Explain how vaccinations help prevent future infections?

Answer 2

Vaccinations involve injecting small amounts of dead or inactive pathogens. These carry antigens, which cause your body to produce antibodies to attack them - even though the pathogen is harmless (since it’s dead or inactive). For example, the MMR vaccine contains weakened versions of the viruses that cause measles, mumps and rubella all in one vaccine. If live pathogens of the same type appear after that, the white blood cells can rapidly mass-produce antibodies to kill off the pathogen.

Question 3

What are the pros of vaccination?

Answer 3

1. They have helped control lots of communicable diseases that were once common in the UK (e.g. polio, measles, whooping cough, rubella, mumps, tetanus..). Smallpox no longer occurs at all, and polio infections have fallen by 99%.
2. Big outbreaks of disease - called epidemics - can be prevented if a large percentage of the population is vaccinated. That way, even the people who aren’t vaccinated are unlikely to catch the disease because there are fewer people able to pass it on. But if a significant number of people aren’t vaccinated, the disease can spread quickly through them and lots of people will be ill at the same time.

Question 4

What are the cons of vaccination?

Answer 4

1. They don’t always work - sometimes they don’t give you immunity.
2. You can sometimes have a bad reaction to a vaccine (e.g. swelling, or maybe something more serious like a fever, or seizures.) Bad reactions are very rare though.